In this paper, we proposed and evaluated a new algorithm (EdgePass) to extract the edges of pass-images for a graphical password system. The EdgePass algorithm is based on an estimated technique for calculating the area in a plane bounded by a graph. This proposed scheme is the first stage of our graphical password system. The system framework is based on Edge detection, Image fusion and high spatial frequency component extraction. The idea of the proposed algorithm is to find whether the process pixel I(x, y) is dark or light. If it is light then the corresponding target pixel I(x,y) is an edge, else it is a background. The experiment results demonstrated the effectiveness of the proposed method. The new method can be stabilized more quickly.